CVE-2026-53123

In the Linux kernel, the following vulnerability has been resolved:

md: wake raid456 reshape waiters before suspend

During raid456 reshape, direct IO across the reshape position can sleep in raid5makerequest() waiting for reshape progress while still holding an activeio reference. If userspace then freezes reshape and writes md/suspendlo or md/suspendhi, mddevsuspend() kills active_io and waits for all in-flight IO to drain.

This can deadlock: the IO needs reshape progress to continue, but the reshape thread is already frozen, so the active_io reference is never dropped and suspend never completes.

raid5preparesuspend() already wakes waitforreshape for dm-raid. Do the same for normal md suspend when reshape is already interrupted, so waiting raid456 IO can abort, drop its reference, and let suspend finish.

The mdadm test tests/25raid456-reshape-deadlock reproduces the hang.